Helmet mounted display system

Abstract

A holographic display system is disclosed. Utilization of holographic elements provides good transmissivity with respect to both outside stimulus and the superimposed display information. Full color display is enabled by a composite spherical lens and the efficient optical coupling of the display information and the pupil allows the weight of the helmet with the display system to be kept to a minimum.

I claim: 
     
       1. A wide field of view reflective composite holographic imaging element possessing optical power, comprising: a) a curved optically transparent substrate having an outer reflection side curved to impart a desired optical power and having an inner side;   b) a first holographic optical element reflective at a first wavelength, said first holographic element comprising a planar holographic mirror when said holographic optical element is formed into a planar configuration, said first holographic optical element being adhered at a first surface to said outer reflection surface and deformed to conform to said curved outer reflection side to have said desired optical power, said first holographic optical element having an outer surface opposite said first surface; and   c) a second holographic optical element reflective at a second wavelength, said second wavelength being different from said first wavelength, said second holographic element comprising a planar holographic mirror when said second holographic optical element is formed into a planar configuration, said second holographic optical element being adhered to said outer surface of said first holographic optical element and deformed to conform to said curved outer surface to have said desired optical power, whereby the focal point and orientation of said deformed first and second holographic optical elements can focus images which are in registration with one another.   
     
     
       2. A wide field of view reflective composite holographic imaging element as claimed in claim 1, wherein said holographic optical elements are substantially monochromatic reflectors. 
     
     
       3. A wide field of view reflective composite holographic imaging element as claimed in claim 2, wherein each said holographic optical element is reflective over a bandwidth of approximately 20 nanometers. 
     
     
       4. A wide field of view reflective composite holographic imaging element as claimed in claim 2, wherein each said holographic optical element is optically transparent outside of the reflective bandwidth. 
     
     
       5. A wide field of view reflective composite holographic imaging element as claimed in claim 1, wherein said two holographic optical elements have different reflective bandwidths, said two holographic optical elements being enclosed between said curved substrate and a protective cover. 
     
     
       6. A helmet mounted, wide field of view, holographic display system comprising: a) a right trichromatic light source;   b) a right target pupil to receive light from said right trichromatic light source;   c) a right optical coupling between said right trichromatic light source and said right target pupil comprising: (i) a right planar beamsplitter positioned in front of said right target pupil and arranged at an oblique angle to a perpendicular to said right target pupil, light passing through said right beamsplitter passing downwardly and to the left away from said right target pupil and the remaining light being reflected thereby;   (ii) a right mirror, optically coupling said right trichromatic light source with said right beamsplitter; and   (iii) a right spherical holographic reflector receiving said remaining light and reflecting and focussing said remaining light back through said right planar beamsplitter to said right target pupil;     d) a left trichromatic light source;   e) a left target pupil to receive light from said left trichromatic light source;   f) a left optical coupling between said left trichromatic light source and said left target pupil comprising: (i) a left planar beamsplitter positioned in front of said left target pupil and arranged at an oblique angle to a perpendicular to said left target pupil, light passing through said left beamsplitter passing downwardly and to the right away from said left target pupil and the remaining light being reflected thereby;   (ii) a left mirror, optically coupling said left trichromatic light source with said left beamsplitter; and   (iii) a left spherical holographic reflector receiving said remaining light and reflecting and focussing said remaining light back through said left planar beamsplitter to said left target pupil;     g) a right framework supporting said right trichromatic light source and said right optical coupling;   h) a left framework supporting said left trichromatic light source and said left optical coupling; and   i) a helmet; said right framework support mounted on said helmet; and said left framework support mounted on said helmet, said left spherical holographic reflector and said right spherical holographic reflector each comprising an optically transparent substrate of a desired optical power, three monochromatic holographic mirror elements adhered to said substrate and taking the power of said substrate, each of said three monochromatic holographic mirror elements corresponding to a different one of the three wavelengths of the trichromatic light from the trichromatic light sources, and an optically transparent protective cover enclosing said three monochromatic holographic mirror elements between said substrate of desired optical power and said protective cover.     
     
     
       7. A helmet mounted display system as claimed in claim 6, wherein said left optical coupling and said right optical coupling further comprise a left relay lens package and a right relay lens package, respectively, the relay lens packages being positioned optically between their respective trichromatic light sources and the mirrors and supported by the frameworks. 
     
     
       8. A helmet mounted display system as claimed in claim 7, wherein said left optical coupling and said right optical coupling further comprise a left prism and a right prism, respectively, the prisms being positioned optically between their respective trichromatic light sources and the relay lens packages. 
     
     
       9. A helmet mounted display system as claimed in claim 6 wherein said left spherical holographic reflector and said right spherical holographic reflector are configured, dimensioned and positioned with respect to said left target pupil and said right target pupil, respectively, to each span at least a forty degree field of vision with respect to each target pupil. 
     
     
       10. A helmet mounted display system as claimed in claim 9, wherein said left spherical holographic reflector and said right spherical holographic reflector are configured, dimensioned and positioned with respect to said left target pupil and said right target pupil, respectively, to each span at least a fifty degree field of vision with respect to each target pupil. 
     
     
       11. A helmet mounted display system as claimed in claim 10, wherein said left spherical holographic reflector and said right spherical holographic reflector are configured, dimensioned and positioned with respect to said left target pupil and said right target pupil, respectively, and to each other to combine to span an 80 degree horizontal field of view with respect to the two target pupils taken together. 
     
     
       12. A helmet mounted display system as claimed in claim 6, wherein said left framework support and said right framework support each comprise two splined rods to accommodate adjustment of said display system and to rigidly maintain an adjustment when in use.